Please see first screenshot of file "incorrect-cut.fcstd"
Part WB cut is applied to Pad and Revolution, which are inside of bodies. This is not allowed and you get the message "Part::Cut: Links go out of allowed scope". A2plus will not import this cut correctly.
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incorrect-cut.png (127.37 KiB) Viewed 1238 times

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Please see second screenshot of file "correct-cut.fdstd".
Part WB cut is applied to Body and Body001. There is no error written to console and this is ok. A2plus imports it fine...
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Hi,
now I got it. Thank you! There remains a question, that is most probably wrong here : If the kind of cut I made is wrong and the result not allowed, why is it not prevented by FreeCAD, even if FreeCAD detects the error? Or is there a reasonable use case for the wrong way? For me it would be very helpful if such thing where prevented, because I _never_ open the report view.

Hi,
now I got it. Thank you! There remains a question, that is most probably wrong here : If the kind of cut I made is wrong and the result not allowed, why is it not prevented by FreeCAD, even if FreeCAD detects the error? Or is there a reasonable use case for the wrong way? For me it would be very helpful if such thing where prevented, because I _never_ open the report view.

IMHO, the Part WB should throw a visible Error Message window for this case.

I'm thankful for @kbwbe's guidance on how to make it right. And I hope to remember it in future.

It seems to me that sub-assemblies do not like balls / spheres. If I have an assembly which contains a ball, where it doesn't matter if it is a Part ball or a handish made PartDesign one, and I include this assembly into an other assembly, the sub-assembly will lose it's colors. If in the sub-assembly the ball is made invisible, after saving and recalculating the master-assembly the visible parts of the sub-assembly will get theirs colors back.

I did first test. I did not only miss the correct colors, i also missed the complete ball at second level import. It has to to with number of faces == 1 for a ball. When i created a drill hole within the ball, it has more than one face and it appears with correct colors.

- The part labels from the tree view can be displayed in the 3D view
(useful for a quick documentation of an assembly via screenshot + partslist)
This are the new buttons:

New-Buttons.png (2.71 KiB) Viewed 899 times

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- improved pointOnPlane constraint: As point definition a sphere (it's center) can be used.
- improved pointOnLine constraint: As point definition a sphere can be used and as line definition an axis of a cylinder.
(This allows more constraining to spheres)
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So even there does not exist a partlist at time of labeling, i could identify the parts (and their files) by screen labels.

But as told before, this works but is perhaps not the standard way of documentation for other users.
One method i know from other machinery docs is to use the POS-number of the partslist to be drawn to the assembly. This is also not very difficult to implement. But in this case partslist has to be done before.

The labeling code could be made dependent on condition whether a partslist exists or not. In latter case the position number could be used. Is that what you are looking for ?